Sensors for water and wastewater monitoring

Water pollution is one of the causes of increased water scarcity. Pollutant monitoring in wastewater discharge is vital to detecting pollution cases for additional remediation management. In the first part of the chapter the most frequently occurring and important water pollutants, their sources and types are summarized and enlightened. The importance of the detection and quantification of the pollutants led to elaboration of sensing and monitoring techniques that can analyze these undesired chemicals at very low concentration with high selectivity. Conventional pollutant detection methods, where water parameters are identified by chemical or laboratory checks done by stationary apparatus, are slow and time-consuming procedures. The developed sensor types, namely chemical-, electrochemical-, and biosensors, have gained considerable attention for saving the environment from pollution through their early detection. Sensors are classified depending on their applications and also according to their transducers. A general summary of reported chemical-, electrochemical-, and biosensors, which have been applied for the recognition of organic and inorganic chemicals, heavy metals, and microorganisms in wastewater, is highlighted. The contribution of nanotechnology in the field of molecular detection is also cited. Nanomaterials, in particular nanofiber-based sensors, in applications in the detection and recognition of toxic pollutants in water are discussed. The up-to-date technique of wireless sensor network is also discussed. Finally, a summary and future forecast on the application of sensors in the detection and monitoring of pollutants in water and wastewater are included.